The manufacture of semiconductor devices involves the performance of a series of process steps using a variety of high tech production and metrology tools in a certain order and often within a certain period of time. The primary function of a wafer logistics system in a wafer fabrication facility, or “fab,” is to deliver the wafers to each of the tools at the right time, as well as to track the location and status of the wafers throughout the process. Automated material handling systems (“AMHS”) are applied to wafer fabs to carry out the automated functions more efficiently, consistently, and safely than can be done via manual means. The fabrication process often results in the need for cross-floor and cross-phase transportation within a single fab and/or cross-fab transportation between fabs.
When a wafer carrier, such as a front opening unified pod (“FOUP”), containing wafers is to be transferred, a manufacturing execution system (“MES”) determines to what destination in the fab the wafer carrier should be transferred. Once the destination decision has been made, the MES sends a transfer request to a material control system (“MCS”), which calculates a detailed transportation route using a route search engine and then notifies a transfer manager to execute the transfer step-by-step. However, typical MES and MCS systems are limited to a single fab and cannot process cross-fab and/or cross-AMHS transportation requests. The MES and MCS systems of one fab are often unable to communicate with the AMHS of a separate fab. In that regard, different fabs may have different AMHS vendors and communication protocols.
Although existing systems and methods have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects.